Conventionally, of semiconductor device substrates, there are those of a type having internal terminals, external terminals and wiring parts formed by metal plating on a metal plate as a base substrate, to be used in manufacturing, for example, a surface-mount type, resin-sealed semiconductor device with ELP (Etched Leadless Package) structure wiring.
Conventionally, a semiconductor device substrate of this type and a semiconductor device using such a semiconductor device substrate are described, for example, in Japanese Patent KOKAI No. 2009-164594 (JP 2009-164594).
In the substrate for a semiconductor device described in JP 2009-164594, on a metal plate, there is formed by plating, from the metal-plate side, an external terminal surface having external terminal parts, on which formed by plating into the same shape is an intermediate layer, on which further formed by plating into the same shape is an internal terminal surface having internal terminal parts. This semiconductor device substrate is configured so that the internal terminal surface having the internal terminal parts, which are to be electrically connected with a semiconductor element, is arranged on the uppermost surface and the height from the metal plate to the uppermost surface is substantially even over the entirety.
In manufacturing of a semiconductor device, the semiconductor device substrate described in JP 2009-164594 is used in a state in which the external terminal surface is in contact with the surface on the metal plate side and, regarding the internal terminal surface, the surface opposite to the metal plate is left uncovered. To be specific, a semiconductor element is mounted on the internal terminal surface side of the semiconductor device substrate, and the semiconductor element mount portion is sealed with a resin after electrodes of the semiconductor element and the internal terminal parts are connected. After sealing with the resin, the metal plate is removed by dissolution by etching or the like, to uncover, on the back surface of the resin for sealing, the external connection surface of the portions formed by plating, which have the internal terminal parts, the wiring parts and the external terminal parts. Thereafter, a resin covering the entirely bare external connection surface is formed, and openings that make only the external terminal parts uncovered is formed.
In practical production, however, if the external terminal surface is formed from the metal plate side and the internal terminal surface is formed by plating on the uppermost layer, the plating thickness varies; when the plating thickness is about 30 μm, for example, the variety in height about 5 to 8 μm is generated. Therefore, when a semiconductor element is mounted and electrically connected with the internal terminal parts, the semiconductor element may be mounted on a tilt or cause a conduction failure in the electrical connection. Further, the processes of forming a resin covering the entire external connection surface and forming openings to uncover only the external terminal parts are required, to lower the productivity for semiconductor devices accordingly.
As described above, according to the semiconductor device substrate in JP 2009-164594, at the uppermost layer, a non-uniform height owing to unevenness during production is generated among the internal terminal surface on which a semiconductor element is to be mounted and the internal terminal parts to be electrically connected with the semiconductor element, to be eventually brought into conduction failure caused by a tilt of the semiconductor element as mounted or a poor connection in bonding. Therefore, an object of the present invention is to provide a semiconductor device substrate and a manufacturing method therefor that can achieve a uniform height over an internal terminal surface on which a semiconductor element is to be mounted and internal terminal parts to be electrically connected with the semiconductor element and that can dispense with a process of forming opening parts for uncovering only external terminal parts, thereby to make it feasible to manufacture a resin-sealed type semiconductor device with high reliability with a decreased number of processes in manufacturing the semiconductor device.
Also, an object of the present invention is to provide a semiconductor device substrate wiring member and a manufacturing method therefor that can achieve a uniform height over an internal terminal surface on which a semiconductor element is to be mounted and internal terminal parts to be electrically connected with the semiconductor element and that can dispense, in a procedure for manufacturing a semiconductor device, with processes of removing a metal plate by etching and of forming opening parts for uncovering only external terminal parts, thereby to make it feasible to manufacture a resin-sealed type semiconductor device with high reliability with a decreased number of processes in manufacturing the semiconductor device.
Also, an object of the present invention is to provide a method for manufacturing a semiconductor device that can eliminate a variety of height owing to unevenness among internal terminal parts to be electrically connected with a semiconductor element, thereby to prevent the semiconductor element as mounted from tilting and to preclude conduction failure resulting from a poor connection in bonding, and to provide a method for manufacturing a semiconductor device that can dispense with a process of forming opening parts that uncover only the external terminal parts.